Machine for surface-finishing road paving



Sept. 2, 1947. A. s. MILLIKIN ET A1. 2,426,703

l I MACHINE FOR SURFACE-FINISHING ROAD PAVING original Filed Nov. 27. 1945 2 sheets-sheet 1 Jahn .56C f/De (sept. 2, 1947. A, s, Mmm kET AL 2,426,703

` MACHINE FOR SURFAC-FINISHING ROAD PAVING Original Filed Nov. 27,' 1945 2 Sheets-Sheet 2 GMW Patented Sept. 2, 1947 MAcHiNE Fon SURFACE-riN-Isi-nuo Roan PAVING Arnold lS. Millikin and John H. Apel, Columbus, Ohio, assignors-to The Jaeger Machine Com-V pany, Columbus, Ohio, a corporation of Ohio Original application November 27, 1943, Serial No. 511,988. Divided and this application, December 26, 1944,A Serial No. 569,298

(Cl. E34- 457) 4 Claims. 1

This invention relates to, road-paving machines and Vmore, particularly to machines employed in the operation of finishing or smoothing the: top surfaces. oi freshly laid beds of roadpavng material, such as asphalt, concrete and the like.

Such machines, as now ordinarily constructed, employ wheeled frames adapted for travel over the rails providedl by spaced molding forms positioned longitudinally at each side of the paving. The frames are each equipped with spaced parallel front and rear troweling screeds disposed substantially at right angles to the length of the roadway. Due to this parallelism in operating positions of the two screeds, the rear or trailing screed is apt to produce or leave the same or equivalen-t irregularities, unevenness or roughness in the upper surface of the new paving as were left therein by the forward screed. Thus, the intended function of the trailing screed is rendered ineffectual to a very considerable degree.

In accordance with the present invention, a road surface finishing machine is provided in which the rear or trailing screed, instead of being disposed in parallel order with the forward screed, is arranged in angular relation therewith, extending diagonally with respect to the` frame of the machine, whereby to enable the rear screed to remove more effectively any irregularities left in the freshly laid paving by the front screed.

It is, therefore, an object of the invention to providea finishing machine for road paving in which the frame of the machine is equipped with a pair of troweling screeds, the front screed being mounted to extend transversely across the paving at an angle of substantially 90 degrees: to the longitudinal axis of the paving and wherein the rear or trailing screed is disposed diagonally of the frame, occupying an acute angle with respect to the front sc-reed.

It is another object of the invention to provide ya finishing machine for road paving employing forwardly and rearwardly disposed reciprocable screeds, and wherein the rear screed has the center thereof mounted for swinging movement about a vertical axis, so that the angularity of the rear screed may be adjusted to various working positions best adapted' for the particular work to be performed.

This application constitutes a true division of our prior application, Serial No. 511,988 filed November 27, 1943.

Withr these and other objects in view, the invention consists in the novel features of construction, combinations of elements and arrange- 2. ments of parts, hereinafter more fully described and pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a top plan view of amachine for finishing highway paving formed in accordance with the present invention;

Fig. 2 is a side elevational view thereof;

Fig. 3 is a fragmentary plan View, disclosing the angularly adjustable rear screed of our improved nishing machine and the supporting and actuating mechanism therefor;

Fig. 4 is a fragmentary vertical sectional view taken. through the adjustable rear screed andits associated actuating` means;

Fig. 45 is a transverse vertical sectional view disclosing the adjustable screed and its supporting means- Referring more particularly to; the drawings, our improved finishing machine comprises, in one of its preferred embodiments, a rectangular frame I0 having track-engagingV wheels I I. In the formation of concrete highways, particularly, metallic forms are placed at the sides of the road bed, and the machine utilizes these forms as trackways for the wheels I I.

The frame of the machine is provided with a power plant such as an internal combustion engine I2. Through a standard clutch-.controlled shift-gear transmission I3, the engine drives shafts I4, by means of which power may be transferred to the traction wheels II to. effect forward or rearward movement of the machine on its supporting rails. The front of the machine includes the usual forward screed I5, which may be of any standard construction; for example, that disclosed in our prior Patent No. 2,299,700, dated October 20, 194,2.

As shown, however, the rear sur-face of the screed I5 is provided with brackets I6 which maintain the screed in contact with vertical thrust-receiving rolls I'I projecting from the front transverse member of the frame I0. The slots formed by the brackets I6 are elongated so that the usual reciprocating motion may be imparted to the screed, such reciprocation being effected by an engine-driven crank I8 with which is connected a crank rod I9, the outer or lower end of the latter having a spring-cushioned connection 20 with the screed, whereby through the rotation of the crank, the screed may be recipro. cated in its horizontal plane of operation, the ends of the screed resting on the wheel-receiving rails. Also, the front member of' thel frame I0 supports av rock shaft ZI carrying cranks 22.y These cranks are linked as at 23 with `the top of the screed, the rock lshaft being oscillated by a piston disposed in a hydraulic cylinder 24,7so that the screed may be raised or lowered as desired. i Since all of the parts so far described are of conventional construction and operation, a more detailed explanation accordingly has been omitted.

A distinguishing feature of the finishing maf chine forming the present invention resides in mounting a rear screed, shown at 25, so that it may be turned about a vertical axis passing near its center so that it may be positioned to extend diagonally of the frame l0, in acute angular relationship to the forward screed l5, or may be positioned in parallelism therewith. In previous types of machines of this character, the rear screed has been located in substantially true f parallelism with the front screed. By varying the angularity of the screed 25 with respect to the screed l5, the loosened or freed paving material engaging the front face of the screed 25 may be advanced toward one or the other of the ends thereof.

The outer portions of the rear screed 25 rest on the track rails when the screed is in active operation. The rear screed is reciprocated by power derived from the engine l2. Thus a power take-off from the transmission i3 drives a sprocket 28 around which passes an endless chain 29, this chain driving a second sprocket 39 xed to a longitudinally extending shaft 3|, journaled in the frame I0. Also, mounted on the shaft 3l, a'djacent to the rear end thereof, is a sprocket which drives a chain 32, the latter passing around another sprocket xed on a short longitudinally extending shaft 33, the latter being rotatably supported in frame-carried bearings 34, as shown in Fig. 4. The forward end of the shaft 33 carries a miter gear 35, which meshes with a similar gear 36 xed to the upper end of a vertically journaled shaft 31, and about the axis of this shaft, the rear screed is adapted to turn, in order that it may be adjusted to assume any of the working positions disclosed in full and dotted lines in Fig. 1.

To impart reciprocatory movement to the rear screed, the bottom of the shaft 37 carries a crank 38 to which is eccentrically connected one end of a rod 39. The other or outer end of this rod is slidably received in the aperture 'of a lug 49 carried by a bracket 4| which is mounted on the rear wall of the screed 25. The rod 39 is provided with collars or nut devices 42 and coil springs are interposed between the lug 40 and the collars or nut devicesV 42 to absorb in part reciprocating thrusts imparted to the rear screed Ywhen the crank 38 is rotated.

Rotatable about the axis of the shaft 37 is a rear screed frame 43 which isV provided with a bearing 44 through which the shaft 37 extends. At its outer ends, the frame 43 is formedV with brackets 45 provided with rollers 46,7the latter engaging the fiat upper surfaces of Ystationary arcuate guides 41 which are carried by themachine frame I9. At the opposite ends thereof, the frame 43 carries vertical thrust rolls 48, which are disposed for engagement with the vertical rear wall of the screed 25, the rolls being positioned within guide brackets 49 projecting from the rear surfaces of the screed 25.

To control the operating positions of the rear screed, `use may be made of a pair of uid pressure cylinders 59. These cylinders are vpivotally connected as at l with the transverse rear mem,-

ber 52 of the frame l0. The cylinders each in' clude a slidable externally projecting piston -rod 53. These rods have their forward ends pivotally connected as at 54 with the rear vertical wall member of the screed 25. Through the operation of suitable control Valves, not shown, fluid may be introduced under pressure into the cylinders 50 to slidably actuate the pistons mounted there- In view of the foregoing, it will be seen that the Ypresent invention provides a finishing and smoothing machine for facilitating, and rapidly and accurately perf-orming, the operations of leveling and removing surface undulations, irreg.

ularities or roughness of road paving. The angularity which the rear screedV may assumeV in oper-A ation overcomes the objections noted with reference to the employment of fixed rear Vscreeds mounted to extend in true parallel relation vwith the front screed by producing an improved finishing and minimizing unevenness in the Vupper surface finishing of the paving.

Weclaim:

l. In a machine for surface nishing newly laid beds of road paving material, a portable frame, a screed, guide means carried by said frame admitting of bodily turning movement of said screed about a substantially vertical axis, means carried by said frame for effecting turning movement of said screed and maintaining the same in its various adjusted positions'and frame--y mounted means for imparting reciprocatory motion to said screed.

2. In a machine for surface finishing newly laid beds of road-paving material, a portable frame, a screed, guide means carried by said frame providing for bodily turning movement 'of said screed about a substantially vertical axis, means carried by said frame for effecting turning movement of said screed and maintaining the same in its various operating'positiofns of adjustment, frame-mounted meansV for imparting reciprocatory motion to saidscreed tobring the same into and out of engagement'withy the material being finished. 'Y

3. InV a machine for surface finishing newlS7 laid beds of road paving material, a portable frame,ra reciprocable screed arranged at the forward end of said frame and disposed substantially perpendicularly to the longitudinal axis of the frame, a second reciprocabl'e'screed ar#Y ranged beneath said frame and disposed rearwardly of said forwardly disposed screed, guide its various adjusted positions of operation, framemounted means forv imparting reciprocatory motion to said screeds, and means for .raising and Y lowering the screeds to bring Ythe same into4 and out of engagement withthe materialsundergoing finishing. i

4. In a machine for surface nishing newly laid beds of road-paving material, a. portable frame, a reciprocable screed positioned at the forward end of said frame with the longitudinal axis of the screed disposed substantially perpendicularly to that of the frame, a second rearwardly disposed screed arranged beneath said frame lbetween the forward and rear ends thereof, a pair of frame-carried arcuate guides having a common axis of curvature origin, a back frame for said second screed turnable on said guides, power actuated means carried by Said frame for imparting reciprocatory movement to said screeds and effecting swinging movement of said second screed about the axis of said guides, and means for raising and lowering said screeds to bring the same into and out of active engagement 'with the materials undergoing nishing. ARNOLD S. MILLIKIN.- JOHN H. APEL.

" REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

